"Yes, here in the frozen north was the earth remolded into the system we now know, before the Western Hemisphere retreated finally behind the Curtain. "And so to us of the Patrol time seems to telescope. The past is with us. We are, in truth, the guardians of the past, for if there is a future--which means change--it lies beyond the Curtain, among the peoples of the Western Hemisphere, who alone now possess the knowledge that could rear and maintain this Wall of Death. Or is it actually, for them, a Wall of Life? What are they doing there in those lost continents? What wonders have they now achieved in their two hundred and seventy years of isolated and unimpeded progress? And what remains as the grand adventure for the rest of us unless it is the penetration--? "Ah, you see, I am very close to utilized. And that nasty word creeps through my mind again, the word we must not whisper among ourselves in the Patrol--strain! Soon, I do not doubt, I shall be back forever in London, washed up much as poor Anstruther was washed up, a victim of proximity to the Curtain. Prepare a pleasant little snuggery for me." But O'Hara was not coming back to London as soon as he pretended to anticipate. I have included these letters from him here only to indicate the acuteness of his mind, how very close he often was to the scientific truths while he rambled on in his most extravagant mood. But this is not a scientific paper--my aim is political, and in particular it is economic, if anyone nowadays distinguishes between the two. My aim is Truth and the revelation of it, as I got it from Emmett O'Hara on that evening of his return, a few days more than one year after he disappeared while flying on patrol out of his base on Wrangell Island. Two days before Christmas, December 23, 2228, I heard that O'Hara had vanished. His father telephoned me as soon as they got the cable, asking if it were possible for me, through the _Observer_, to obtain further information. I was able to learn a few details, but there wasn't much to learn. O'Hara had left the International Patrol's base at Wrangell on a routine long-distance flight toward the Curtain at 12:15 P.M., December 20th. His flight pattern called for him to proceed to the seventieth degree of latitude and to fly along it until his scintillometer recorded .250 milliroentgens an hour, which was the maximum permissible even for a veteran. He was then to pivot westward, proceeding for three hundred miles along the Curtain's fringe, then turn back toward Wrangell and arrive by 1 P.M., the slow time because he would be taking readings constantly and must keep his craft well throttled to do it. He took off with an excessive fuel load, for his rank as a captain permitted him to make any necessary extensions of his flight, subject to confirmation of the change by wireless.